(a) Field
The invention relates to a display device, and more particularly, to a display device which displays an image and generates a sound or vibration.
(b) Description of the Related Art
Display devices have been developed from a cathode ray tube (“CRT”) type using an existing cathode ray tube to various flat panel display devices such as a liquid crystal display (“LCD”), a plasma display panel (“PDP”), an organic light emitting diode (“OLED”) display, an electrowetting display (“EWD”), an electrophoretic display (“EPD”), an embedded micro cavity display (“EMD”), and a nano crystal display (“NCD”).
The LCD which has been in the limelight among the flat panel display devices has advantages such as reduced size, reduced weight and low power consumption. With such advantages, the LCD has gradually received attention as a replacement means capable of overcoming a disadvantage of the existing CRT. The LCD is mounted and used on almost all information processing apparatuses requiring a display device.
The LCD includes a LCD panel which generates an electrical field in a liquid crystal material between an upper substrate including a common electrode, a color filter and the like, and a lower substrate including a thin film transistor, a pixel electrode and the like, and applying different electrical potentials to the pixel electrode and the common electrode to change alignment of liquid crystal molecules in the liquid crystal material. As a result, the LCD displays images by controlling transmittance of light through the changes in alignment of the liquid crystal molecules.
In the LCD, since the LCD panel is a non-emissive element which does not emit light itself, the LCD further includes a backlight unit provided below the LCD panel for supplying light to the LCD panel.
Since the OLED display among the flat panel display devices includes a light emitting diode which emits light itself, the OLED display has an advantage in that the backlight unit is not used.